Most everything I've read regarding porting says that only the total volume of ports matters, the location is pretty irrelevant. If that's true it would probably have no effect, unless you screwed the process up somehow, then you'd have damaged or reduced the efficency of your cab for nothing.

You'd waste quite a bit of time and effort, you may screw up the tuning of the cab (if you don't exactly duplicate the ports) and you'll reduce the cab's rigidity this increasing nasty resonances and colouration. And even if you do it right, it won't sound better. The ports are so small relative to the frequencies that they output that their output is omnidirectional and thus their location all but irrelevant.